High power pulse generating systems are used to generate the output signals irradiated by antennas in radar jammers, impulse radar and high power microwave weapons. Such systems require high output levels and usually have a large number of pulser units arranged in arrays with combined outputs. Higher output power requirements by radar jammers necessitate greater numbers of pulser arrays, and greater system costs. Modern electric warfare requires impulse radar and jamming systems having increasingly higher output power levels. To limit system cost, it is necessary to improve the performance of the pulser units.
The simplest form of pulser unit is shown in FIG. 1. The energy storage portion 10 is charged from an external source, not shown in FIG. 1. At an appropriate time, switch 11 is closed, discharging the stored energy into load 12. After discharge, switch 11 is opened and the energy storage portion recharged. Arrangements for charging the energy storage portion and control systems for operating switch 11 are both well known.
The repetition rate of the pulser unit is determined by the time necessary to charge the energy storage portion to an appropriate level and the time necessary to discharge the stored energy into the load. These time periods are determined by the nature of the energy storage portion as well as the nature of the switching device. The output power of the pulser unit is defined as EQU P=E/t (in watts)
where t is the discharge time of the energy stored portion and E is the amount of energy stored (in Joules).
One way of maximizing the output power of a pulser unit is to make the discharge time period t as short as possible. This appears to be the most practical approach to increasing pulser unit output since there are upper limits on the amount of energy that can be stored in any practical energy storage device.
Conventional pulser units consist of discrete energy storage portions such as capacitors and switches of various types. As is well known, it is very difficult to achieve high power, high energy density pulser units using discrete components. In order to generate the narrow pulses required to facilitate high power outputs, it is necessary to use a large number of pulse shaping stages, also discrete components. These additional pulse shaping stages add substantially to the cost of the pulse generating system, lower energy density and render the combination of pulser units less efficient.
The lower energy density caused by discrete components and plural pulse shaping stages results in substantially greater space requirements for large systems. Since many of the components in a large pulse generating system are physically separated, triggering coordination and interconnections between components become more complex and greater electrical losses occur as systems increase in size.
As in any system using multiple generation units, important factors in a high power pulse generation system are the energy density of the overall system and the efficiency of the pulser units. Modern impulse radar, radar jammers and microwave weapons systems require marked improvements in both factors to economically supply the high output power demanded in electronic warfare.